Pen



FIG. 1 is a top, front, left perspective view of a pen in accordance with my design;

FIG. 2 is a top, rear, right perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a right side elevational view thereof, with the left side elevational view being a mirror image thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a top, front, left perspective view taken from the same direction as FIG. 1 showing the two parts of the design separated for clarity; and,

FIG. 7 is a top, right, rear perspective view showing the two parts of the design separated for clarity. 

CLAIM The ornamental design for a pen, as shown and described. 